meh. as they allude to, 2L is about the size that a modern motor can produce enough hp to cruise at steady state with little/no boost, allowing low emissions and higher mileage.
there still is not substitute for displacement. gimme 7.4L and parts to bolt on and the upper power limit will be hit sooner, easier and far exceeded. to be practical, from a longevity standpoint, 1L/1000lbs should be the lower limit. but since we live in a disposable society...
Case in point, ford is touting a tiny v6 'weak-o-boost' truck motor in the f150 that can tow what the V8 does. however, feedback indicates it does so at 9-11mpg with a 3000-4000lb towed load. well gee, my 454 suburban with no OD does that...so we gained?